Steel alloy and process of making the same



Patented Mar. 6, 1928.

UNITED STATES PATENT OFFICE.-

EDMUND IPAKULLA, OF REMSCHEID, GERMANY, ASSIGNOR, BY MESNE ASSIGNMENTS,

TO DEUTSCHE EDELSTAHLWERKE AKTIENGESELLSCHAFT, OF BOCHUM, GER- MANY, A CORPORATION OF GERMANY.

STEEL ALLOY ANDQROCESS OF MAKING THE SAME.

No Drawing. Application filed September 18, 1924, Serial No. 738,525, and in Germany June 9, 1923.

My invention relates to steel alloys and the rocess of making the same, and more particularly to alloys of the character and composition of high speed steels. As 1s known to those skilled in the art high speed steels such as are now in use have very poor magnetic properties. The object of the improvements is to manufacture a steel of the character and composition of high speed steels which shows valuable magnetic propcertain sorts of steel must be heated in orderto lower the Ar -transformation when coolin the steel.

articularly the alues of the coercive force imparted to the high speed steel by my improved process are such that my; improved steel is superior in quality to good chromium or tungsten steel.

Further, I have found that the magnetic roperties of hi h speed steel are improved y adding cobalt to the steel, the coercive force of the steel being increased in a degree as the proportion of cobalt in the steel is increased. ll Example 1.A high speed steel containing 0.7% O, 12% W0 and 4% Or has been heated at 1100 centigrade and quenched in oil. It showed the' following ma netic values: remanence 6550, coercive orce 91.5,

product of remanence and coercive force '40 599x10.

Ewample 2.-A high speed steel containing 0.7% C, 0.3% Mn, 0.25% Si, 7% M0, 4.5% Cr, 1.5-2% Co was heated at 1150 centigrade and uenched in oil. It showed a remanence of 000, a coercive force of 90, and the product of both 630.10

Ewample 3.-A high speed steel containing 0.8% C, 7% Mo, 4% Cr, and 5% Co, after being heated and quenched, showed a rema- 5 nence of 6800 to 7500, a coercive force of 100 to 110, and the average product of both was 730.10.

Ewample 4.--A high speed steel containing 0.6 to 0.8% C 0.5% Mn, 0.25% Si, 4 to 5% Cr, 7 to 8% M0, 1 to 2% 00, 0.5 V was heated at 1150 centigrade, and quenched in oil. It showed he following magnetic values: remanenee 7'000, coercive force 90.

I claim:

1. The process of manufacturing permanent magnets, which consists in heatin high speed steel containing chromium an at least one of the elements tungsten, molybdenum or cobalt at a temperature above lowering temperature, and uenching the same in mild non-aqueous har ening agents.

2. The process of manufacturing permanent magnets, which consists in heating'70 high speed steel containing 0.6 to 0.8% G, 0.5% Mn, 0.25% Si, 4 to 5% Cr, 7 to 8% Mo,'1 to 2% Co and 0.5% V at a temperature of 1150 centi ade, and quenching the same as set forth a ove.

In testimony whereof I hereunto aflix my EDMUND PAKULLA.

signature. 

